1. Field
Example embodiments of the following description relate to a signal processing apparatus and method providing a spatial impression, and more particularly, to an apparatus and method for increasing a spatial impression of an original signal by artificially adding a reverberation effect to the original signal.
2. Description of the Related Art
As audio devices continue to develop rapidly, a demand for providing a spatial impression to sound is increasing. To provide the spatial impression to sound, generally, a reverberation effect is artificially added to an original signal. In this case, a listener may feel as if the sound is being listened to in a concert hall. That is, the spatial impression may be provided to the listener by intentionally adding the reverberation effect to an original signal, such that the listener may feel as if the sound quality is similar to that of a concert hall.
Examples of conventional methods for adding the reverberation effect to the original signal will be introduced.
In a first example of a conventional method, a signal processing apparatus may generate a left reverberation signal and a right reverberation signal, by applying the reverberation effect to a left original signal and a right original signal, respectively, both of which are stereo signals. Next, the conventional signal processing apparatus generates a final left signal by summing the left original signal and the left reverberation signal with a proper ratio, and generates a final right signal by summing the right original signal and the right reverberation signal with a proper ratio.
According to this method, directivity of the left original signal and the right original signal may be maintained since the reverberation effect is independently applied to the left original signal and the right original signal. However, a large memory capacity is required to apply the reverberation effect to both the left original signal and the right original signal. In particular, because the first example method requires a rather large memory capacity, it is inappropriate for a mobile device, which is strictly limited in terms of resources.
The second example of a conventional method provides a signal processing apparatus, which may sum the left original signal with the right original signal, and then apply the reverberation effect to the summed signal. Next, the signal processing apparatus may delay the summed signal to which the reverberation effect is applied, and perform orthogonal summing between a delayed summed signal and a non-delayed summed signal, thereby generating the left original signal and the right original signal.
According to the second example conventional method, a smaller memory capacity is required, as compared to the memory capacity required in the first example conventional method, since the reverberation effect is applied to the summed signal. Also, the second conventional method is less complicated. However, directivity of the signals may be damaged because the reverberation effect is applied with the same ratio irrespective of a difference in sound pressure between the left original signal and the right original signal.
Accordingly, when the reverberation effect is applied to provide a spatial impression to an original signal, a method that requires a relatively small memory while maintaining directivity of the original signal is demanded.